Electric-arc lamp



2 Sheets-Sheet 1.

(No Model.)

J. T. MCCONNELL.

ELECTRIC ARC LAMP.

No. 288,826. Patented Nov. 20, 1888.

JAW- 951mm Q m. wnhinitm O. C

(No Model.) 2 Sheets-Sheet 2.

J. T. MO OONNELL. ELECTRIC ARC LAMP.

No. 288,826. Patented Nov. 20, 1883.

I I r E 2 "I ll M i v I 1 h 1 i II T v I 'l I F E I I v! LIV c I JV w:f7W,

UNITED STATES PATENT OEEicE.

JOSEPH T. MCCONNELL, OF PITTSBURG, PENFSYLVANIA.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 288,826, dated November20, 1883.

Application filed July 14,1883.

To all whom, it may concern:

Be it known that I, JosErH T. McGoNNELL, of Pittsburg, in the county ofAllegheny and State of Pennsylvania, have invented certain new anduseful Improvements in Electric-Arc Lamps and I do hereby declare thatthe following is a full, clear, and exact description of the invention,which will enable others skilled in the art to which it appertains tomake and use the same, reference beinghad to the accompanying drawings,which form apart of this specification.

The object of this invention is to provide electricarc lamps with adevice which shall operate to cut out the electrodes when the arcbecomes so long as to endanger any of the parts, especially the coil ofwire in derivation around the electrodes, when the feeding mechanismsticks or in any way becomes irregular in its action and fails toperform its functions properly, when a portion of either electrodedisrupts from the body thereof, when either electrode falls from itssupport, or, in, fact whenever from any cause the circuit through theelectrodes of the lamp assumes such a condition as to abnormally absorbthe general current, and thus reduce the power of other lamps in thesame circuit and tend to destroy its own mechanism; and, further, myobject is to effect the relighting of any such faulty lamp the instantits electrodes shall come together, and to effect this instantaneouslywith unerring certainty.

It is only where two or more lamps are operated in series that the wantis felt of any automatic device having the foregoing general character.My aim is to accomplish all the required operations incident torelighting after cutting out by means entirely mechanical, and therebyavoid all the uncertainties of electrical action, dispensing with thenecessity of accurately proportioning the parts, and avoid ing theuncertain results of oxidation or bad contacts, and to at the same timeeffect a reliable and instantaneous relighting of the lamp the momentthe electrodes come in contact.

To these ends my invention consists, briefly, in providing anormally-open path of low resistauce around the electrodes and placingtherein two points of closure, one of which shall be made by theabnormal movement of (No model.)

the armature of either the usual regulatinghelix or the derivation-helixof high resistance, and the other of which shall be made by the lowerelectrode and broken by the pressure of the upper electrode thereon. Theconsequence will be that the by-path established will be mechanicallyruptured by the very fact of contact of the electrodes, so thatpractically there is at any moment only a single path open to the maincurrent.

The invention further consists in the ar rangement and combination ofdevices for the above and other ends, as hereinafter fully described andclaimed.

The invention may be put in practice in a great variety of ways; but Iwill confine my description to the illustration of one simple form. Allthe working parts of a form of regulating mechanism are shown in thedrawings; but the present invention concerns only so much as relates tothe automatic switching of circuits, the remaining parts being shownmerely to make clear the relative positions of the mechanisms of thelamp.

Figure l of the drawings is a partly sectional elevation of the upperportion of an arc-lamp, and Fig. 2 a similar but reduced view of thelower portion. In these views the position adopted for illustration isthat of normal arc, the operative lever of the mag net system standingin position of normal equilibrium. Fig. 3 is a detail of the cuttingo.it device applied to the armature of the main electro-magnet, showingthe position assumed to effect the cutting out of the electrodes.

A is the top plate, and B the bottom plate, the two rigidly connectedtogether by suitable standards or parts. (Not shown in the drawings.) Tothe plate A are screwed, 011 the respective sides of the center, themain helices O of low resistance in the electrode-circuit, and thehigh-resistanee helices D in a derived circuit between the positive andnegative terminals of the lamp. A bracket, E, attached to the plate A,serves as a pivotal support for a horizontal lever, F, whose ends arerespectively connected to the suction-cores a and yoke b of helices O bymeans of the post 0, Fig. 3, and to the suction-cores (Z and yoke e ofhelices D in a similar manner. A vibrating lever, f, has one end pivotedto a fixed support, and rests upon a curved surface on le 2 wa es ver F,the other end of the lever f being connected to the standard g, whichprojects upwardly from the box 71/, which surrounds the toothedcarbon-rod G. In the box it is journaled a small pinion engaging therackteeth on rod G, and on the shaft of this pinion, outside the box 71,is an escape-wheel, t. On standard 9 is pivoted the escapement-anchorit, having the pendulum-bobs Z. A gravitating detent, m, is pivoted onan extension, 02, of box h, and normally engages the wheel t, as shown.By this means the energizing of helices 0 draws up cores a and yoke band elevates that end of lever F, thus lifting the lever f, and with itbox h and its pinion,which, being-locked by detent m after the firstmovement, lifts with it rod G and establishes the arc. Regulation isaccomplished by the action of the derivation-helices D, which, when thearc. tends to become too long, predominate in attraction, and, throughthe cores (Z and yoke e, pull up that end of lever F and cause the otherend of said lever to descend, thus lowering the rod G. The continuedattraction of helices D in this manner eventually brings the toe o ofdetent on against a stop, 1), and momentarily withdraws the detent fromwheel t, upon which the weight of the rod G acts as motor and tends toturn it, its speed being then regulated by the momentum-es capement k Z.Thus the proper length of are is maintained.

As the foregoing construction is the subject of a separate jointapplication to be filed, I will not herein go into details. In such alamp my invention is applied in the following manner: The helices O arepreferably wound on metallic spools, one or both of whose heads (1 areconnected directly to the positive binding-post or terminal, as shown,the spools being well insulated from the plate A. The post a isinsulated from yoke b, but fitted so that the yoke 12 has a slightvertical play, in order that the initial movement of the cores to andyoke 12 shall not affect the post 0. A metallic plate or washer, r, isattached to the insulated portion of post 0, so as to be under yoke b.IVhen the yoke b is in unattracted position, as in Fig. 3, it rests incontact with the plate 9", as shown. Plate r has a vertical pin, 8,depending from it, and against the pin 8 bears a contact-brush, z, fixedon an insulated post, a, set in plate B of the lamp, so that in allpositions of the post a there will be contact between pin 8 and brushit. From the latter an insulated wire, o, passes down along or throughone of the side rods of the lamp.

The lower crossbar, H, at the bottom of the lamp, forms, as usual, thesupport for the lower carbon, I but the carbon-holder K, instead ofbeing fixed, as in all non-focusing lamps, is arranged so as to havevertical play. The metallic socket M receives and guides the stem y ofthe metallic carbon-holder K, and is insulated from the cross-bar II, asshown, being connected by screws to the insulated washer z, whence aninsulated conductor, 1;, passes directly up to the negative binding-postor terminal of the lamp. The wire 1; terminates at the insulated screwN, which screws a spring, P, which extends under the stem y. Aninsulating-pin, a, in the lower end of stem 3 bears always upon thespring P, and the tension of the latter is such as to steadily hold upthe stem y, carbon-holder K, and carbon I, except when the upper carbon,T, is resting on the carbon I. There is then. the additional weight ofthe carbon T and its rod G bearing 011 the spring P, and it yields. Thenthe spring P is supporting only the negative carbon I, holder K, andstem 0 it makes contact at c with z, and such position of contact is theposition always maintained while the electrodes are separated. Theinstant, however, that the electrodes come together the contact at c isforcibly opened by the additional weight of carbon T and rod G. hen thelamp is illactive, having no current, the short circuit through c isopen, and the normal circuit is then from the positive terminal throughhelices O, thence by brush (1 to rod G, to carbon T, carbon I, holder K,socket M, washer 2, wire 12, to the negative bindingpost. Helices O areenergized, and the first attraction breaks the connection between plate0' and yoke I), and its further attraction lifts rod G and carbon T andestablishes the are. This action lifts the extra weight off carbon I,and spring Pmoves upwardly and makes the contact at 0,- but no circuitexists, because there is a break at another point-namely, at r b. Thecircuit through the carbons remains as the only one of low resistancefor the current to take. Now, if from any cause whatever this circuitshould fail or the arc become too long, either the failure or weakeningof attraction for cores a and yoke b or the predominant attraction forcores d and yoke 6 causes the lowering of the cores (4 and yoke b, andthe contact at 1' b is made. This establishes ashort circuit then frompositive bindingpost to q, to a a, to Z, to r s, to t, to a, to o,thencebywireoto spring P, through a to wire 1;, thence to negativeterminal, affording a short circuit around the main helices O and theelectrodes. As the helices O are cut out through the failure at the are,the contact at r b will remain and reliably maintain the short circuitas long as the carbons are held from contact. Should the defect becomeself-remedied and the positive carbon T feed down into contact withcarbon I, thus bringing the lamp into normal condition again, theinstant the weight of carbon T and rod G bears on carbon I the contactat c is broken and the current is transferred into helices O, whichinstantly attract the cores a and yoke I), thus also breaking thecontact at 1- I). In practical operation these two breaks at c and 1- 6occur at the same time, and my experience has demonstrated that no sparkis produced at either point. The instantaneous attraction of cores a andyoke 2) effects the establishment of the are, since the current has nochoice of circuits, for the whole current IOC Lil

(leaving helices D out of consideration) must pass through helices O. Inthis establishing of the arc, both at the first lighting or anyrelighting, the movement of the parts must be sufficient to allow forthe slight rise of the negative carbon due to the elasticity of thespring I; but this play, as well as that of the parts r I), need be butvery small, owing to the absence of any tendency to form a spark at therupture of contact at c or 1' I). The relighting of the lamp istherefore removed out of the uncertain realm of divided electriccircuits and relative resistances, and is effected with the absoluteprecision of mechanical laws. The short circuit established by r I) mustunfailingly be broken at the very instant it should be, and at thatinstant only-namely, when by the de scent of the positive carbon thelamp is restored to an operative condition. In the absence of suchrestoration the short circuit remains; but I wish it to be understoodthat the presence of any resistance in said short circuit has noinfluence whatever on the making and breaking of said circuit or itsmaintenance, since at no time has the current a choice of circuits.There is but one circuit open at a time. hen one opens the other closes,and vice versa.

IVhile I have shown and described a particular assemblage of devices forthe purpose of bringing my invention into practical effect, I by nomeans confine the scope thereof to any single assemblage or combination,as the mere construction and arrangement of devices may be greatlyvaried.

I11 the present application, and in applica tion filed July 30, 1883, bymyself and Thos. J. McTighe,certain details are shown common to bothforms of lamps. I therefore herein disclaim as of this applicationwhatever is shown and describedin said application of myself and Thos.J. McTighe, and not herein specifically claimed.

I claim as my invention 1. In an electric-arc lamp having a feedingmagnet in the electrode-circuit, a short circuit around the electrodes,having two breaking-points in series, one adapted to be closed by theweakening of the feeding-magnet or the abnormal strengthening of ahiglrresistance derivation-magnet, and the other adapted to be opened bythe pressure of one electrode upon the other and closed by theirseparation, substantially as described.

2. In an electric-arc lamp, a short circuit around the electrodes,providedwithItwobreaking-points in series adapted to be opened atsubstantially the same instant, as set forth, whereby the formation of aspark is prevented upon opening said circuit.

3. In an electric-arc lamp, the combination, with the lower electrode,of a vertically-movable holder adapted to yield slightly when the upperelectrode bears upon the lower, substantially as described.

4. In an electric-are lamp, the combination of a movable lower ornegative carbon-holder, a short circuit around the electrodes, and aswitch in said circuit adapted to open to the pressure of the uppercarbon and to automatically close upon the relief of such pressure,substantially as described.

5. In an electric-arc lamp, the combination, with the lower or negativeelectrode, a holder therefor adapted to a limited range of motion, and aspring adapted to normally support said electrode and holder and at thesame time close a switch, but to yield to any additional weight and atthe same time open said switch, sub stantially as described.

6. In an electric-are lamp having a helix in the electrode-circuit, anarmature for said helix, and a movable device on said armature, saidarmature and movable device constituting aswitch in a short circuitaround the electrodes and said helix, one of said parts being adapted toopen the switch by the electromagnetic attraction exerted upon thepassage of current in said helix, substantially as described.

7 In an electric-arc lamp having a helix in the electrode-circuit, anarmature, a movable device on said armature, said armature and movabledevice constituting a switch in a short circuit around the electrodesand said helix, and adapted to close upon the abnormal weakening orfailure of current in said helix, a movable lower electrode, and aswitch in said short circuit adapted to remain normally closed while anarc exists, and to open upon the impact of the electrodes, substantiallyas described.

8. In an electric-arc lamp, a main actuating magnet, O, in theelectrode-circuit, a lever, F, adapted to communicate the energy of thehelix to the electrode, an armature, a b, for said helix, and aninsulated post, 0, connecting said armature with the lever, saidarmature having a slight play, in combination with a short circuitaround the said helix, and electrodes passing from the armature to thesaid insulated post, substantially as described, whereby when current isabsent from the helix the short circuit is closed between the armatureand post, and when the helix is energized the short circuit is rupturedby the attraction first exerted on the armature.

9. In an electric-arc lamp, the combination of magnet G, lever F,armature a b, insulated post 0, having plate '2', and suitable connections, said magnet 0 being in direct circuit with the electrodes, andsaid armature a b and plater constituting a movable switch in a shortcircuit around the said magnet and electrodes, substantially asdescribed.

In testimony that I claim the foregoing as my own I have hereto affixedmysignature in presence of two witnesses.

JOSEPH T. McCOXXELL.

\Vitnesses:

T. J. McTrcnn, Tnoams J. Pxr'rnnsox.

